12779945 has 4 divisors (see below), whose sum is σ = 15335940. Its totient is φ = 10223952.

The previous prime is 12779941. The next prime is 12779947. The reversal of 12779945 is 54997721.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9078169 + 3701776 = 3013^2 + 1924^2 .

It is a cyclic number.

It is not a de Polignac number, because 12779945 - 2² = 12779941 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12779896 and 12779905.

It is not an unprimeable number, because it can be changed into a prime (12779941) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1277990 + ... + 1277999.

It is an arithmetic number, because the mean of its divisors is an integer number (3833985).

Almost surely, 2^12779945 is an apocalyptic number.

It is an amenable number.

12779945 is a deficient number, since it is larger than the sum of its proper divisors (2555995).

12779945 is an equidigital number, since it uses as much as digits as its factorization.

12779945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2555994.

The product of its digits is 158760, while the sum is 44.

The square root of 12779945 is about 3574.9048938398. The cubic root of 12779945 is about 233.7991860806.

It can be divided in two parts, 12779 and 945, that multiplied together give a triangular number (12076155 = T₄₉₁₄).

The spelling of 12779945 in words is "twelve million, seven hundred seventy-nine thousand, nine hundred forty-five".